In the prior art it is known to use natural and/or man-made organic staple fibers. Natural staple fibers such as wool, cotton and kapok are well known. In particular, these fibers are used both for weaving garments and for making padding. In common usage, natural fibers are preferred over synthetic ones, both due to pollution and biodegradability concerns, since these fibers are totally organic, and for being hypoallergenic and biocompatible.
As mentioned above, natural fibers are used in the manufacture of padding due to their high heat insulating properties.
For example, the Kapok fiber is a totally organic plant fiber obtained from the seed pods of the plant by the same name, also known as ceiba pentandra and has a single cell structure (meaning that each fiber is composed of a single cell). The length of a Kapok fiber ranges between 10 and 30 mm, has a diameter between 20 and 40 microns, and is shaped like a thin hollow sheath. In other words, the kapok fiber has a substantially tubular shape.
The peculiarity of being hollow ensures excellent properties to the Kapok fiber, such as high heat insulation, good elasticity and buoyancy and good water repellency features. This combination of excellent properties is not found in any of the other natural staple fibers usually used (e.g., wool and cotton).